Micro-electro-mechanical-systems (MEMS) sensors often rely upon the precise measurement of micro-displacements of a sub millimeter flexible component. Commonly employed methods include measurements of the charge on a variable capacitor, the resistance of piezoresistor, and, more rarely, tunneling of current through an air gap.
Optical sensing technologies exhibit several inherent advantages in comparison with these techniques, such as environmental ruggedness, passivity, resistance to electromagnetic interference, light weight, small size, low power consumption, wide bandwidth, and high sensitivity. However, minimization and integration of large-scale optical sensors with small MEMS devices represents a challenge. Recent studies on such integration include waveguides and optical fibers for various pressure [1-4] and acceleration [5] detectors.